Technical Abstract:
Broiler carcasses with different types and numbers of bacteria are commonly chilled together in an ice water bath which may lead to transfer of bacteria from carcass to carcass. Historically, chill tanks have been chlorinated to help prevent cross contamination. Recently other chemical additive options have become available to help lower bacterial counts during the chilling process. The objective of this study was to test the effectiveness of a proprietary chemical additive (T-128) to lower numbers of Salmonella and Campylobacter transfer in chill water. To test this, eight containers were prepared each containing two broiler wings, water, and ice in a weight to weight ratio of 1:2:4 chicken meat to water to ice. One of the two wings was inoculated with approximately 106 cells each of an antibiotic resistant strain of Salmonella and Campylobacter; the second wing was left uninoculated. Two containers were assigned to each of four treatments, as follows: control (no additive), 50 parts per million (ppm) chlorine, 0.5% T-128 (by volume), and a combination of 50ppm chlorine and 0.5% T-128. All containers were covered and shaken at 130 rpm for forty-five minutes. After 45 minutes of agitated chill treatment, each wing was rinsed in 30 mL of PBS; antibiotic resistant marked Salmonella and Campylobacter were enumerated per mL by plating on BG-Sulfa agar with the addition of nalidixic acid and Campy-Cefex agar with the addition of gentamicin, respectively. This specifically measured transfer of the two inocula from wing to wing through several varying wash environments. Following control chill treatment, a mean of log 2.9 cfu of both Salmonella and Campylobacter were detected per mL of un-inoculated wing rinse. Chlorine addition alone resulted in a 1.9 log decrease in Salmonella and a 2.4 log decrease in Campylobacter detected on un-inoculated wings. T-128 applied alone did not cause a significant decrease in Salmonella numbers but resulted in a 2.6 log decrease in Campylobacter. Compared to the control treatment, the combination of T-128 and chlorine was the most effective treatment resulting in a 2.3 log decrease in Salmonella and a 3.0 log decrease in Campylobacter numbers detected from un-inoculated wings. T-128 used in conjunction with chlorine may have the ability to control cross contamination of poultry carcasses with human pathogens during immersion chilling.